 export function add(a,b){
    let c=a+b

     console.log(c)

 }

 export function jian(a,b){
     let c=a-b

     console.log(c)

 }

 export function cheng(a,b){
     let c=a*b

     console.log(c)

 }

 export function chu(a,b){
     let c=a/b

     console.log(c)

 }